Aging-US: GPA peptide inhibits NLRP3 inflammasome activation to ameliorate colitis11-10-2020
Aging-US recently published "GPA peptide inhibits NLRP3 inflammasome activation to ameliorate colitis through AMPK pathway" which reported that pyroptosis and NLRP3 inflammasome are associated with various kinds of inflammatory diseases including colitis.
In vivo, the authors found GPA peptide could exert anti-inflammatory effects on DSS-induced mice colitis, and its anti-inflammatory effects are abolished in NLRP3-/- mice.
In macrophage, GPA suppresses the assembly of NLRP3 inflammasome and GSDMD cleavage.
Furthermore, GPA maintains mitochondrial homeostasis through inhibiting ROS, mtDNA and NLRP3 mitochondrial localization, with other signals related to NLRP3 inflammasome unaffected.
The Aging-US results suggest that GPA inhibits NLRP3 inflammasome activation through increasing AMPK phosphorylation to suppress ROS, and can be applied in the prevention of colitis through targeting NLRP3.
Dr. Jian Peng from The Department of Animal Nutrition and Feed Science at The College of Animal Science and Technology within Huazhong Agricultural University as well as The Cooperative Innovation Center for Sustainable Pig Production - both in Wuhan, Hubei, China said, "Ulcerative colitis (UC) is a chronic and idiopathic inflammatory disease that affects colon, resulting in weight loss, diarrhea, rectal bleeding, and abdominal pain."
Pyroptosis, an inflammatory cell death, can lead to cell membrane rupture, then ends to the release of cell contents and a large number of inflammatory factors, such as IL-1β and IL-18.
Figure 7. Putative mechanism for the anti-inflammatory effect of GPA in macrophages. GPA increased AMPK phosphorylation to suppress ROS and mtDNA production, resulting in the blocking of NLRP3 mitochondrial translocation, which inhibited NLRP3 inflammasome activation and pyroptosis.
Pyroptosis activation coordinates mucosal immune to defend intestines from infection, resulting in infected epithelial cells extrusion, and the fact that infected epithelial cells or macrophages are swallowed by neutrophils.
Meanwhile, pyroptosis is overactivated in macrophages, it results in the production of a large number of pro-inflammatory cytokines, followed by the activation of immune cells in the lamina propria, and the disruption of the intestinal epithelial structure and intestinal homeostasis.
However, in an intestinal pathological condition, ROS, as signal molecules, activate the inflammatory pathway to amplify inflammatory response and damage the intestinal structure.
Meanwhile, in intestinal macrophages, ROS, as a molecular signal, activates the NLRP3 inflammasome and secrete IL-1β and IL-18, resulting in pyroptosis and amplification of inflammatory response.
The Peng Research Team concluded in their Aging-US Research Paper, "GPA ameliorates DSS-induced colitis in a NLRP3-dependent manner. GPA increases the phosphorylation of AMPK, where it blocks ROS and mtDNA production as well as NLRP3 mitochondrial translocation, leading to suppressing NLRP3 inflammasome activation and pyroptosis in macrophages (Figure 7). Our results suggest that GPA could be potentially used for the prevention of colitis."
Full Text - https://doi.org/10.18632/aging.103825
Correspondence to: Jian Peng email: firstname.lastname@example.org
Launched in 2009, Aging-US publishes papers of general interest and biological significance in all fields of aging research as well as topics beyond traditional gerontology, including, but not limited to, cellular and molecular biology, human age-related diseases, pathology in model organisms, cancer, signal transduction pathways (e.g., p53, sirtuins, and PI-3K/AKT/mTOR among others), and approaches to modulating these signaling pathways.